Fire damper blades and special frame

ABSTRACT

Fire damper blades and special frame for use in a safety fire damper assembly wherein a first embodiment involves substantially identical blades that are interlocked at the ends thereof, one to the other, wherein each blade end is comprised of an arcuate section extending for approximately 180* to form a semi-circle and terminating in a tab which partially closes the semi-circle, with the arc being essentially truly circular. In one form, a blade assembly having the foregoing construction the various blades will rotate, one on the other, for at least 180* to provide the greatest theoretical coverage for a given blade width. In this form of the invention each blade is essentially identical. In another form of the invention, one blade end will be as previously described, but the other blade end will terminate in a tab which covers a greater portion of the semicircular opening and which includes a further tab extension which is bent back over the original tab to provide a double fold. In this form of the invention the blades will rotate with respect to each other for only about 120*, but this will form a more rigid structure that may be necessary under certain conditions.

United States Patent 91 Rapp et a1.

[ 1 Jan. 1,1974

1 FIRE DAMPER BLADES AND SPECIAL FRAME [76] Inventors: Fred E. Rapp, Andorra Rd.,

Lafayette Hill, Pa. 19444; William V. Bault, 1300 Prospect Hill Rd., Villanova, Pa. 19085 [22] Filed: May 17, 1971 21 Appl. No.: 144,148

[52] US. Cl. 160/235, 160/229 [51] Int. Cl E061) 9/00, E05f 15/20 [58] Field of Search 160/1-6,

[56] References Cited UNITED STATES PATENTS 1,144,090 6/1915 Anderson 16/178 1,205,707 11/1916 Cahill 160/235 X 1.666.211 4/1928 K'ellogg.... 16/178 UX 2,586,561 2/1952 Poggi 160/235 X 3,467,163 9/1969 Vassaux 160/5 X 3,485,284 12/1969 Turner et a1. 160/235 X 3,525,378 8/1970 Root 160/1 3,538,975 11/1970 Metti 160/207 X FOREIGN PATENTS OR APPLlCATlONS 1,468,002 12/1966 France 160/235 Primary ExaminerDennis L. Taylor Attorney-Caesar, Rivise, Bernstein & Cohen [5 7] ABSTRACT Fire damper blades and special frame for use in a safety fire damper assembly wherein a first embodiment involves substantially identical blades that are interlocked at the ends thereof, one to the other, wherein each blade end is comprised of an arcuate section extending for approximately 180 to form a semi-circle and terminating in a tab which partially closes the semi-circle, with the are being essentially truly circular. In one form, a blade assembly having the foregoing construction the various blades will rotate, one on the other, for at least 180 to provide the greatest theoretical coverage for a given blade width. In this form of the invention each blade is essentially identical. In another form of the invention, one blade end will be as previously described, but the other blade end will terminate in a tab which covers a greater portion of the semi-circular opening and which includes a further tab extension which is bent back over the original tab to provide a double fold. In this form of the invention the blades will rotate with respect to each other for only about 120, but this will form a more rigid structure that may be necessary under certain conditions.

4 Claims, 9 Drawing Figures PATENTEUJAH 1mm v 3,782,444.

SHEET 1 or 5 M/VENTORS FRED 5. RAPP WILL/AM v. aAuLr TTORNEYS- AIENIEU H914 3.782.444

WW] 2 BF 5 n) INVEN 70/?5 FRED 5. RA PP WILL/AM v, BAULT A TTOR/VEYS.

PATENTEDJAN 1 m4 SHEEI 3 0F 5 INVE NTORS FRED vE. RAPP 7 B) WILL/AM V. FAULT awwy, 02am,

ATTORNEYS.

PATENTED JAN 1 1974 sum or 5 INVENTORS FRED E. RAPP WILL/AM v. BAULT ATTORNEYS.

FIRE DAMPER BLADES AND SPECIAL FRAME The present invention further contemplates a special blade pack which occupies an extremely small volume when in the compacted or folded condition. In the special blade pack there is provided outer blades having the previous construction, but being somewhat narrower. Inner blades are then provided having the previous construction, but being of standard width. There is also provided a middle blade which is slightly longer than the standard length blades, but wherein one blade end opens in an opposite sense from the other blade end.

Finally, the present invention also encompasses a special frame packaging construction wherein the headpiece and blade assmelby are secured together and the remaining three sides of the frame may be separately provided with there being means to achieve a simple connection between the headpiece and the remaining part of the frame.

The present invention relates to fire damper blades, special fire damper blade assemblies and frames of a novel construction that are adapted to accommodate the fire damper blades of the present invention or fire damper blades heretofore used.

It is known to provide fire damper assemblies that are presented as quick unfolding fire walls or dampers that may be installed in air delivery structures such as conduits, ducts or ventilating openings which run through fire walls in buildings. Such fire walls are adapted to be actuated at a predetermined temperature so that the con-duit, duct or opening will not be vulnerable to fire when the fire wall itself is resistant to fire. It is further known to provide folding walls comprised as a plurality of hingedly interconnected strips which unfold in a zigzag or accordian arrangement. Examples of such construction are set forth in U.S. Pat. Nos. 1,205,707, 2,586,561, 3,273,632 and 3,485,284.

The foregoing patents as well as others suggest the various forms for the edges of the blades comprising a damper wall, but the problem still remains of facilitating production in the economical sense.

Still another problem involves maintaining the fire damper blades in an extremely compact condition, but still allowing such blades to be actuated to form the fire damper wall in a quick, simple and reliable fashion.

Furthermore, it has been determined that the fire dampers of the prior art are comprised of a frame that must be specially constructed, thereby adding to the expense of the assembly.

It is accordingly an object of the present invention to provide fire damper blades which will occupy a minimum space'and yet which will unfold quickly to constitute a fire damper wall.

Still another object of the present invention is to provide fire damper blades that can be easily constructed at low cost.

Still another object of the present invention is to provide fire damper blades having ends comprised essentially of an arcuate section in the nature of a true semicircle, such that the blades will rotate for at least 180 with respect to each other or, in some cases, for only about 120 to provide a more rigid structure.

Still another object of the present invention is to pro vide a special frame for a fire damper assembly which consists essentially of a headpiece and a blade assembly secured to the headpiece and wherein the remaining three sides of the frame may be separately provided and in some cases may be simply a U-shaped piece of metal that is prepared in the field.

The foregoing as well as other objects of the invention are achieved by providing fire damper blades and a special frame wherein substantially the identical blades are interlocked at the ends thereof, one to the other. In this embodiment of the invention, each blade end is comprised of an arcuate section that extends for approximately 180 to form a C-shaped construction of approximately 180, with the blade end then terminating in a tab which partially encloses the semi-circular area of the C-shaped construction. In this form of the invention the C-shaped arc is essentially truly circular, thereby effecting great economies in production. In this form of the invention, the blades will rotate with respect to each other for at least 180 when the assembly is actuated, and in this way, the greatest theoretical coverage for a given blade width is achieved.

In the foregoing form of the invention, each blade is essentially identical. Another embodiment of the invention also involves identical blades generally constructed in accordance with the first embodiment, but wherein the tab includes a tab extension which is bent back over the original tab to provide a double fold. In this form of the invention, the blades will rotate with respect to each other for only about to provide a more rigid structure.

In yet another embodiment of the invention, a special blade pack is provided which occupies an extremely small volume in the folded condition. This embodiment of the invention basically involves five blades, the outer ones of which are essentially constructed in accordance with the first embodiment of the invention, but somewhat narrower. Inner blades are then provided having the previous construction, but being of standard width. The outer blades as well as the inner blades are disclosed to face each other. Finally, there is a middle blade which is slightly longer than the standard length blades, but wherein one blade end opens in an opposite sense from the other blade end.

The special frame of the invention involves a head portion having a blade assembly secured thereto. The blade assembly may be constructed in accordance with the present invention or may be comprised of blade assemblies of the prior art. The head portion includes receptable means or bent over edges that receive one edge ofa connecting piece at each end of the head portion. Another edge of the connecting piece is received in a U-shaped member which constitutes the remaining three sides of the frame. It is contemplated that the connecting piece may take on various forms, and in one form the connecting piece is so constructed that the U- shaped frame is simply formed from a three-sided or channel shaped member. In such a case, the connecting piece will have an edge that is received by the head portion, and the connecting piece will further include offset fingers that will receive the U-shaped channel member constituting the remainder of the damper frame.

Other objects of the invention will become more readily apparent when viewed in accordance with the accompanying drawings wherein:

FIG. 1 is a perspective view showing a fire damper blade assembly constructed in accordance with a first embodiment of the present invention and secured to a frame, with the fire damper blade assembly having been brought to the unfolded condition, and wherein the frame is secured to a duct;

FIG. 2 is a plan view of the fire damper assembly of FIG. 1, on a somewhat reduced scale, but taken at a time when the blade assembly is in the folded condition;

FIG. 3 is an enlarged sectional view taken along the lines 3-3 of FIG. 2, with certain blades removed or partially shown for the sake of clarity;

FIG. 4 is a fragmentary view, similar to a portion of FIG. 3, but wherein the blades have been actuated to move from folded to unfolded condition and showing in fragmentary view the connection between a blade member that is secured directly to one end of an actuating spring, and a second blade member secured to the first-named blade member, with the second blade member being in the process of moving to the unfolded or wall forming condition;

FIG. 5 is an exploded perspective view showing a special frame constructed in accordance with the present invention;

FIG. S-A is a fragmentary perspective view showing another form ofa connecting member that can be used with the special frame;

FIG. 6 is a sectional view showing the relative rotation of two blades constructed in accordance with the present invention and particularly showing how the blades rotate with respect to each other along the interconnected edges thereof;

FIG. 7 is a sectional view showing another form of the invention wherein the tab enclosing the semicircular curled edge includes a tab extension folded back over the tab wherein rotation of the blades relative to each other is for but 120 to provide a more rigid assembly; and

FIG. 8 is a sectional view showing a special blade pack which is somewhat more compact.

Referring now in greater detail to the various figures of the drawing wherein like reference characters refer to like parts, there is generally shown at 10 in FIG. I a fire damper assembly secured to duct or conduit 12. It will be seen that the fire damper assembly 10 basically comprises a frame 14 which contains or carries a fire damper door 16 comprised of individual blades 18 that are interconnected together. As can be seen from a comparison of FIGS. 1 and 2,the blades 18 may either be in the folded or inactive position of FIG. 2 or the unfolded or active position of FIG. I wherein the blades 18 when taken together constitute a fire damper door.

As will be seen. the fire damper assembly also includes ramps 20 so that the fire damper door will be led in a rocking arrangement, and in this way the fire damper door will be held in the closed position, thereby acting as a safety wall to prevent the passage of fire.

The type of fire damper assembly 10 shown in FIGS. 1 and 2 is the so called horizontal type since the fire damper door 16 will be created-by movement of the blades 18 in a generally horizontal sense from the folded condition of FIG. I. to the unfolded condition of FIG. 2. Such movement is achieved by means of an actuating spring 22 of the linear type (FIGS. 3 and 4) that is sold by Hunter Spring Company of Lansdale, Pennsylvania under the mark NEGATOR."

In the first embodiment of the invention, as shown in FIG. 3, the individual blades are shown as being interlocked, one to the other, with the first blade being secured to the actuating spring.

In many cases, the fire damper door will open verti cally, such that a spring is not needed since the door will close itself under the force of gravity, and furthermore, in most cases the locking mechanism may even be dispensed with since the weight of the blades is usually sufficient to prevent the door structure from undue movement against pressure directed against it.

The details of the frame 14 are best shown in FIGS. 1 and 5 wherein the frame 14 is shown as including headpiece 24, sides 26 and 28 and bottom piece 30. It will be seen that in one embodiment of the invention the side pieces 26 and 28 as well as bottom piece 30 are provided as a single continuous strip with appropriate folds.

FIG. 2 shows the frame 14 when the blades 18 are held close to headpiece 24 by means of a clip 32 which extends about the compacted bundle of blades 18 as shown in FIG. 2. Connecting links 34 are secured to the clip 32, and as shown in FIG. 3, links 36 extend across frame 14. The links 36 are secured together through fusable fire link 38 which is secured to the links 36 by means of S-clips 40 or in other ways known to the art.

As best shown in FIG. 3, a blade 18 is secured to end 42 of spring 22 through fastener 45. Each succeeding blade is interconnected, one to the other, at the ends thereof as illustrated in FIG. 3.

Thus, when fusable link 38 ruptures at a predetermined temperature, spring 22 becomes effective to pull the blades away from their collapsed condition of FIG. 2 in order completely to close opening 46. In actual standard Underwriters Laboratories tests, the damper door created by the opening of blades 18 will resist a high pressure hose stream in accordance with such tests.

As the damper door unfolds from left to right as viewed in FIG. 1, the leading blade 18 will be forced along edges 44 of the ramps 20, after having previously been guided along inner edges 46 of the frame 14.

As shown in FIG. 3, the ramp 20 possesses a tooth 50 projecting from edge 48. The tooth 50 serves to lock the opened fire damper wall in the open position since the tooth 50 will engage hinged connections 52 between adjacent blades 18.

It is to be noted that the blades 18 of FIG. 3 are identical in every respect, and this identity of construction achieves substantial economies.

The interlocking engagement of adjacent blades 18 can be best seen in FIGS. 4 and 6. It is to be initially noted that each blade end 60 is of true semi-circular configuration extending from blade width 62. The outer end of the semi-circle is then bent back toward width 62 in first and second tabs 64 and 66 respectively. It is to be noted that second tab 66 is somewhat wider than first tab 64, and thus second tab 66 covers a greater proportion of semi-circular opening 70 than the tab 64 covers semi-circular opening 72. Furthermore, it is to be noted that the tab 66 is spaced somewhat above semi-circular opening 70 whereas tab 64 is spaced somewhat into semi-circular opening 72. It will be seen from FIG. 4 that the tab 66-A of blade l8-A, being constructed in the same manner as tab 66 and related to the width of its blade in a similar manner, slips easily into the semi-circular opening 72 to achieve an interlocking fit.

From a study of FIG. 6 it will be seen that the ends of the blades 18 and 18-A rotate upon each other and relative to each other in such a way that the blade l8-A (shown in phantom in FIG. 6) will ride approximately half way around the blade 18 with short tab 64-A in contact with long tab 66, and then the blade 18-A will simply drop down to a position constituting a total rotation of 180 to achieve the diametrically opposed position of FIG. 6. This can be understood by following through positions A to E of both blades 18 and 18-A of FIG. 6.

It should be noted that position A from blade 18-A is essentially the position of blade 18-A when it is in the folded or inactive position of FIG. 2 or as generally illustrated in FIG. 3. In such a position, the tab 64-A essentially rests against tab 66 of blade 18, and semicircular opening 72-A of blade 18-A opens out in the same sense as semi-circular opening 70 of blade 18. As the blade l8-A rotates through positions B, C, D and E, the short tab 64-A still makes at least line contact with the longer tab 66 of the blade 18. When position is reached, the dropping down occurs (under the urging of spring 22 or gravity) so that the remainder of rotation for the blade 18-A is simply a drop to the inverted fall line position of FIG. 6 wherein short tab 64-A of blade I8-A makes full surface contact with tab 66 of blade 18.

It will be seen from FIG. 6 that the blades 18 and IS-A are securely interlocked at the ends thereof. Furthermore, the blades have now moved from the nesting position of FIG. 3 wherein the respective semi-circular openings of the interlocked blades open out in the same way to the activated full line position of FIG. 6 wherein the semi-circular openings open out in opposite senses and the blades are alternatively inverted with respect to each other when the fire damper wall is erected through the rupture of fusable fire link 38 under the urging of spring 22 or gravity.

By virtue of the semi-circular construction as set forth hereinabove, the blades of the present invention avoid any problems of close fit or rocking.

Attention is now called to FIG. 7 wherein one end of the blade is modified to provide a tab extension 80 which extends from the tab 66-8 in a double fold through connecting end 82. It will be seen that the outer edge 84 of the tab extension 80 serves to restrict the relative rotation of the blades 18 so that shoulder 86 of the blade 18 abuts the tab extension 80 near end 84, and in this way, the rotation of the tab 18 is limited to 120 or any other rotation.

While a rotation of 120 requires the presence of additional blades since the width of each blade is not being used to a maximum degree, nevertheless, the resulting fire damper door where the blades rotate with respect to each other for I is more rigid, and this is sometimes a very desirable feature.

Attention is now called to FIGS. 5 and 5-A which show special frame packaging construction in accordance with another embodiment of the invention. Here a bundle of blades 18 is provided in combination with headpiece 24. As shown in FIG. 3, the headpiece 24 is so formed as to include a curled edge and grasping means 90 which serves to receive a tab 64 of the blade 18 that is closest to the headpiece 24. The opposing edge 92 is so bent to provide a slot 94. A similar slot 96 is provided adjacent the curled edge 90. As shown in FIG. 5, the slots 94 and 96 serve to receive a connecting piece 98 which possesses legs 100 and 102. The leg 100 is tightly received in the slots 94 and 96 and a crimp may be provided to insure the joint.

In order to erect a frame 14 it is a simple matter to provide the side pieces 26, 28 and 30 from a strip that is simply bent at corners l 10 and 112 to provide a three sided member which receives the headpiece 24 to complete the frame.

As further shown in FIG. 5, the side members 26 and 28 are so formed as to possess slots and 122 which receive the leg 102 of connecting piece 98 in order to provide a tight four side frame. Again, suitable crimping may be used as indicated at and the crimps in headpiece 24 are indicated in 132.

It will be readily apparent that while it is preferred that the blades used in connection with the special frame package construction of FIGS. 5 and 5-A be constructed in the manner as shown in FIG. 3, nevertheless, blades of any suitable construction, such as in any of the four U. S. Patents specified hereinabove, may be used.

In an alternate form of the invention, as shown in FIG. S-A, the connecting piece possesses a leg 142 that is received in the slots 94 and 96 in the manner of FIG. 5. However, tongues 144 constituting a portion of engaging means extend at right angles from the leg 142, with an offset finger 146 bending also from the leg 142. In this embodiment of the invention the side and end walls of the frame are constituted simply by using U- shaped stock which consists of web 150 and side legs 152. It will be seen that the web 150 is simply slipped between the extensions 144 and finger 146, and a crimp can be used to complete the joint.

By virtue of the arrangement of FIGS. 5 and 5-A, it is possible to achieve further economies since only the combination of the headpiece and the blades need be manufactured at a remote point. The remaining three sides of the frame can be made in the field, and the frame then completed in the field, simply with the addition of a separately supplied ramp 20 and spring 22 thereby achieving further economies.

Attention is now called to FIG. 8 which shows another embodiment of the invention wherein the blades are interlocked together in the same manner as the blades of FIG. 3, and the blades rotate with respect to each other in the same manner as illustrated in FIG. 6. However, it should be kept in mind that any blade configuration capable of achieving a full rotation may be utilized in the special blade pack of FIG. 8. In examining FIG. 8 it should be noted that the special blade pack may be provided with the headpiece 24 that includes the curled edge or grasping means 64. The special blade pack itself consists of outer blades 210 which are constructed essentially the same as blades 18 except that the blades 210 are somewhat narrower in width than the blade 18 which can be regarded as being of standard width. However, in FIG. 8 the inner blades 18 are of the same width and construction as the blades 18 of FIG. 3. Finally, a central blade 212 is provided which, while being of essentially the same width as the blades 18, possesses ends that open outwardly in opposite senses.

The advantage ofthe special blade pack of FIG. 8 lies in the extremely compact condition in which the blade pack is maintained since the blade pack of FIG. 8 closely approaches the theoretical minimum space that is necessary to house the blades in the inactive condition. It will be seen that the blades of FIG. 8 occupy a height equal to a little more than the thickness of the width of each blade plus the height of two blade ends.

Travelling from curled edge 90 it will be seen that the blade 210 possesses first end 60 curled in the usual semi-circular form and terminating in tab 64 that partially encloses the semi-circular opening 72. Furthermore, as in FIG. 4, the tab 64 is spaced somewhat within the semi-circular opening 72. The second end 60 of the blade 210 possesses a tab 66 in the manner of FIG. 4.

As previously stated, the inner blade 18 is of standard construction so that the tab 64-A of the blade 18 nests within tab 66 of the blade 210. The other end of the upper blade 18 terminates in the tab 66-A.

The middle blade 212 possesses at one end a short tab 64-B that is nested within tab 66-A of first inner standard blade 18. The other tab 64-B of the middle blade is located parallel of the tab 66 and is nested within .tab 66-C of the other standard blade 18.

The remainder of the special blade pack comprises another standard blade 18 having tabs 64-C and 66-C. Finally, the other outer blade 210 possesses tabs 64-D and 66-D, with the tab 64-C nesting within the tab 66-D.

It will be seen that the foregoing construction, while not constituted of identical blades as the embodiment of FIG. 3, does offer the advantage of extreme compactness in the inactive position. One of the outer blades 210 is simply secured to the spring 22 in the manner of FIGS. 3 and 4.

It can be seen from the foregoing that the present in vention provides a series of highly usable and versatile blades and frame assemblies. Certain of the blade assemblies of the present invention offer the unique advantage of rotation with respect to each other of a full 180 and even slightly more, or in the event ofa smaller rotation, the advantage of more rigid structure. The special frames of the present invention offer advantages of economy and quick assembly in the field. Finally, it is observed in FIGS. 1 and that the frame of this invention is secured together without using fastening members and instead is held together by crimping or other pressure techniques.

Without further elaboration, the foregoing will so fully illustrate our invention that others may, by applying current or further knowledge, readily adapt the same for use under various conditions of service.

What is claimed as the invention is:

l. A fire damper blade assembly comprising a plurality of planar blades having long edges defining the width thereof, said blades being interlocked, one to the other, at the edges thereof, each blade including two end portions, one end portion comprised of a first arcuate section extending for only approximately 180 to form a true semi-circle, said first semi-circular arcuate section terminating in a tab that partially closes the semi-circle, said tab extending for about one half of the width of the semi-circle, being in a plane parallel to the plane of said blade, and being spaced slightly below the width of the blade so that the arc of the first semicircular section is slightly less than l, the other end portion including a second semi-circular arcuate section and a second tab extending more than halfway across the width of said second semi-circular section and being spaced above the width of the blade so that the arc of the second semi-circular section is slightly greater than and wherein said first tab is positioned within the semi-circular area defined between said second tab and said second arcuate section when two of said blades are interlocked at the edges thereof.

2. The fire damper blade assembly of claim 1 wherein each blade is identical.

3. The fire damper blade assembly of claim 1 wherein one of said blades is secured to a headpiece constituting a portion of a frame and wherein said blades are maintained either in an inactive folded position or are actuated to move to an open position wherein each blade rotates a true 180 with respect to each other.

4. The fire damper blade assembly of claim 3. where said blades and headpiece are assembled together as a unit, with the remainer of the frame being added at a later time. 

1. A fire damper blade assembly comprising a plurality of planar blades having long edges defining the width thereof, said blades being interlocked, one to the other, at the edges thereof, each blade including two end portions, one end portion comprised of a first arcuate section extending for only approximately 180* to form a true semi-circle, said first semi-circular arcuate section terminating in a tab that partially closes the semi-circle, said tab extending for about one half of the width of the semi-circle, being in a plane parallel to the plane of said blade, and being spaced slightly below the width of the blade so that the arc of the first semi-circular section is slightly less than 180*, the other end portion including a second semi-circular arcuate section and a second tab extending more than halfway across the width of said second semi-circular section and being spaced above the width of the blade so that the arc of the second semicircular section is slightly greater than 180* and wherein said first tab is positioned within the semi-circular area defined between said second tab and said second arcuate section when two of said blades are interlocked at the edges thereof.
 2. The fire damper blade assembly of claim 1 wherein each blade is identical.
 3. The fire damper blade assembly of claim 1 wherein one of said blades is secured to a headpiece constituting a portion of a frame and wherein said blades are maintained either in an inactive folded position or are actuated to move to an open position wherein each blade rotates a true 180* with respect to each other.
 4. The fire damper blade assembly of claim 3 where said blades and headpiece are assembled together as a unit, with the remainer of the frame being added at a later time. 